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Q: Wondering why my 2005 GTO is overheating and isnt blowing heat after2thermostats on 2005 Pontiac GTO

I replaced a thermostat about 2 months ago after my 2005 gto overheated i just had to replace it again the other day , but this time it wasnt the problem. when my heat is all the way up it still blows cold air and my car overheats i need to know what the problem is. besides the water pump or heater core im running outta ideas.
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Did you bleed all the air out of the cooling system? This will cause a vehicle to overheat. It would help if you told us if the car ran normal and if it overheats after replacing the thermostate.
I'm having the same issue as goat05. I drive a 06 gto and yesterday, all of a sudden the temp gauge shot up to "H" and the system alert went off. I then noticed the heater wasn't blowing cold air, even when the car had been at operating temp for quite some time. I went ahead and changed the t-stat, drained all coolant, filled everything back up to appropriate levels and burped the system for about 30 mins. During the burping, the first 20 mins the car was at the right temp (right b/t 1/4 mark and 1/2 mark on the gauge, where it's always been) then all of a sudden the temp started to rise again and fall again. I went and checked the hose that runs from the radiator to the water pump and noticed i didn't feel any water running through and it was semi-cool to the touch. If coolant was constantly flowing through the hose, you wouldn't be able to hold on too long correct? I'm guessing the water pump has gone out, but looking for feedback before I start the process of replacing the water pump. *Also, during the burping phase when the radiator cap was off, I noticed the water wasn't constantly moving through the system. I would stay at the same level for a long period of time. Is it also possible the water pump could be clogged up? I've read other threads that the Dex-One coolant can build up and gunk up over time. Any feedback would be greatly appreciated.
Having the exact same issue myself. Had the car's radiator replaced last November but they didn't replace the thermostat (160 degree because of supercharger). Everything seemed to be fine until the other day when it sat, running, for about 15 minutes. Temp gauge gradually started going over the half mark and upwards. Started down the road and it went back to normal pretty quickly. Added a little coolant that night in the burp box and seemed to be fine. Then did the same thing yesterday. I replaced the accessory fan last year also, cost over $500. Talked to my Chevy tech and he thinks it might be the fan's switch failing. Fans don't seem to come on, at least not at the noise level they normally did. Very frustrating..........
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